During a short stay made last year in Leyden, I was enabled, through the courtesy of Mr. Ritsema, to examine the types of the Pentatomidae in the Leyden Museum, described by the late Snellen van Vollenhoven. Various doubtful species were thus identified and observations of previous authors controlled on the types. So a large part of the identifications hereafter quoted, were already made by C. Stal, who received from van Vollenhoven a number of his types for examination. I thought it would be useful for hemipterists to have for the van Vollenhoven’s species a revision like the one Mr. Distant is publishing on Walker’s types in the British Museum. Curiously enough, a number of the species described in the year 1867 [published 1868? 1)] by the dutch entomologist, were described at the same time by Walker in the British Museum’s Catalogue: I think it very probable that the names given by Walker take priority, though I could not ascertain it.